function diffImage(img)
{
    if(img.src.match("http://www.photoscartoon.com/wp-content/uploads/2014/06/tom-and-jerry-cartoons.gif")) img.src = "http://www.photoscartoon.com/wp-content/uploads/2013/11/angry_birds_characters.jpg";
    else img.src = "http://www.photoscartoon.com/wp-content/uploads/2014/06/tom-and-jerry-cartoons.gif";
}